It is known, especially in road building and road repair installation, to join adjacent sections of concrete, for example, by mechanical means such as dowels and grout. In one example, the transverse upright end of an existing slab is drilled to receive dowels that will project away from the slab to interlock with the newly poured slab. Each drilled hole is somewhat larger than the dowel so as to provide room for grout or adhesive material. It is commonplace to employ a retainer disk slipped over each dowel to abut the end of the old slab for the purpose of retaining the grout. Each such disk has a central circular opening having a tight fit over its dowel and the opening further has a radial notch which provides what is known as a weep hole to vent the grouted dowel of air and excess grout. There are several disadvantages flowing from the nature and use of prior retainers, mainly arising from difficulties in installation, poor dowel-to-disk fit, displacement of the disk via retrograde movement along the dowel, etc.
It is a principal feature of the present invention to provide an improved retainer that eliminates the disadvantages of the prior art, primarily by the design of a disk that is relatively stiff but flexible and that has a central dowel-fitting opening formed to "wipe" the dowel during installation on the dowel and to grip the dowel so as to prevent inadvertent retrograde movement on the dowel after installation. The portion of the disk bordering the opening is of greater flexibility than the remainder of the disk, which materially minimizes breakage, chipping, etc., of the disk during installation. Increase in flexibility of the opening-bordering area of the disk results from providing the bordering flange with radial slits or notches which serve also as weep holes.
Further features, objects and advantages of the invention will become apparent as a preferred embodiment is disclosed in the ensuing description and accompanying drawings.